1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

//! FunctionRegistry trait

use datafusion_common::Result;
use datafusion_expr::{AggregateUDF, ScalarUDF};
use std::{collections::HashSet, sync::Arc};

/// A registry knows how to build logical expressions out of user-defined function' names
pub trait FunctionRegistry {
    /// Set of all available udfs.
    fn udfs(&self) -> HashSet<String>;

    /// Returns a reference to the udf named `name`.
    fn udf(&self, name: &str) -> Result<Arc<ScalarUDF>>;

    /// Returns a reference to the udaf named `name`.
    fn udaf(&self, name: &str) -> Result<Arc<AggregateUDF>>;
}